(Reuters) - Indivior’s U.S. subsidiary has filed lawsuits against firms seeking approval for generic versions of its opioid addiction treatment Suboxone, which generates 80 percent of the drugmaker’s revenue.
The patent lawsuits were filed against Dr. Reddy’s, Allergan Plc’s Actavis Laboratories, Endo International’s Par Pharmaceutical, Alvogen Pharma US, Teva Pharmaceutical Industries and Mylan NV.
The lawsuits allege that these companies have infringed a patent that relates to an oral film containing buprenorphine and naloxone, the key constituents of Suboxone, the London-listed drugmaker said in a statement.
Shares of the company slipped when the market opened on Friday before edging into positive territory.
Indivior, which launched the first buprenorphine-based product to treat opioid dependence in 1996, has been involved in patent infringement litigations with the same companies over other patents related to the Suboxone film.
“We strongly believe that these companies with their proposed generic products infringe on our intellectual property and we are taking the appropriate actions to enforce our position,” Indivior Chief Executive Shaun Thaxter said.
Shares in Indivior, which was spun out from Reckitt Benckiser in 2014, crashed 40 percent on Sept. 1 after the drugmaker said a U.S. court ruling could clear the way for Dr. Reddy’s generic rival.
Indivior said then that the ruling meant it would not be able to rely on patents to prevent Dr. Reddy’s from making a generic alternative to Suboxone Film, unless the judgment is reversed on appeal.
Thaxter said the company was preparing to file it with the U.S. Court of Appeals for the Federal Circuit shortly after the court judgment is entered.
Dr. Reddy’s bought the abbreviated new drug application (ANDA) for a generic rival to Suboxone from Teva Pharmaceutical in June 2016 for $70 million.
Reporting by Justin George Varghese in Bengaluru; editing by David Clarke